Concerns have been recently raised regarding the postoperative decrease in platelet count after aortic valve replacement (AVR). Thus, a retrospective analysis was conducted of patients after AVR with regards to postoperative platelet count.
METHODS: The data were analyzed from all patients undergoing AVR with (n = 829) or without (n = 1,230)
coronary artery bypass grafting (CABG) at a single center between January 1998 and May 2009. The lowest (minimum) platelet count within the first five postoperative days was determined.
RESULTS: The patients received either an ATS mechanical
prosthesis (ATS; n = 401), a St. Jude Medical mechanical
prosthesis (SJM; n = 791), a Carpentier-Edwards Perimount
bioprosthesis (CEP; n = 618), a Medtronic Freestyle stentless
bioprosthesis (FRE; n = 213), or a Sorin Freedom Solo stentless
bioprosthesis (SFS; n = 36). By using a multivariate linear regression model, the following independent risk factors for a lower postoperative platelet count were revealed: age, body surface area, active
endocarditis, preoperative platelet count, duration of
extracorporeal circulation, number of grafts, valve size, and units of transfused fresh-frozen plasma and red blood cells. On entering the type of
prosthesis into the multivariate linear regression analysis, together with the other risk factors, patients with CEP and FRE valve
prostheses had a lower minimum postoperative platelet count than those with mechanical
prostheses (ATS and SJM).
CONCLUSION: Patients undergoing AVR with the Carpentier-Edwards Perimount
bioprosthesis or a Medtronic Freestyle stentless
bioprosthesis had a lower minimum platelet count within the first five postoperative days, compared to patients receiving ATS and St. Jude Medical mechanical
prostheses. No differences were identified between the Sorin Freedom Solo and all other valve
prostheses.